A guy in Wichita told me our ADS-B test sets get sent in every 24 months, and I found the FAA memo to back it
Pulled up AC 20-165B after a hangar talk in Wichita and it says the same thing, so half our shelf units are out of date and I didn't know it. How are you all tracking calibration dates across multiple tail numbers?
Man, that binder story hits close to home because we had the same thing happen when our shop went from two tails to five. A shared sheet with the send date plus a phone alarm has been the only thing that keeps us honest, and yeah, one person has to own it or it falls apart. AC 20-165B doesn't leave much room to argue, so the reminder system is really the whole ballgame.
A buddy of mine ran a small shop with six planes and found out the hard way when a ramp check caught two units past the 24 month window. He had a paper log in a binder that stopped getting updated after they picked up the third tail number, and nobody wanted to be the one to chase it down. What finally worked for him was a shared spreadsheet with the send-in date and a phone reminder set 60 days out, sounds dumb but it caught two units last year before they lapsed. AC 20-165B is pretty clear on the interval, the hard part is just having one person own the list.